BACKGROUD Fusaruside is an immunomodulatory fungal sphingolipid which has medical potentials for treating colitis and liver injury, but its poor natural abundance limits its further study. RESULTS In this study, we described a synthetic biology approach for fusaruside production by engineered Pichia pastoris that was based on polycistronic expression. Two fusaruside biosynthesis genes (Δ3(E)-sd and Δ10(E)-sd), were introduced into P. pastoris to obtain fusaruside producing strain FUS2. To further enhance the yield of fusaruside, three relevant biosynthetic genes (Δ3(E)-sd, Δ10(E)-sd and gcs) were subsequently introduced into P. pastoris to obtain FUS3. All of the biosynthetic genes were successfully co-expressed in FUS2 and FUS3. Compared to that produced by FUS2, fusaruside achieved from FUS3 were slightly increased. In addition, the culture conditions including pH, temperature and methanol concentration were optimized to improve the fusaruside production level. CONCLUSIONS Here a novel P. pastoris fusaruside production system was developed by introducing the biosynthetic genes linked by 2A peptide gene sequences into a polycistronic expression construct, laying a foundation for further development and application of fusaruside.

中文翻译：

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工程化毕赤酵母生产的fusaruside（一种选择性免疫调节剂）。

BACKGROUD Fusaruside是一种免疫调节性真菌鞘脂，具有治疗结肠炎和肝损伤的医学潜力，但其天然丰度差，限制了其进一步的研究。结果在这项研究中，我们描述了一种基于多顺反子表达的工程化毕赤酵母生产合成呋喃二糖苷的生物学方法。将两个岩藻糖苷生物合成基因（Δ3（E）-sd和Δ10（E）-sd）引入巴斯德毕赤酵母中，以获得产生岩藻糖苷的菌株FUS2。为了进一步提高岩藻糖苷的产量，随后将三个相关的生物合成基因（Δ3（E）-sd，Δ10（E）-sd和gcs）引入巴斯德毕赤酵母中以获得FUS3。所有生物合成基因均在FUS2和FUS3中成功共表达。与FUS2产生的相比，从FUS3获得的富沙鲁糖苷含量略有增加。此外，优化了pH，温度和甲醇浓度等培养条件，提高了洋紫苏苷的生产水平。结论在这里，通过将由2A肽基因序列连接的生物合成基因引入多顺反子表达构建体中，开发了一种新型的巴斯德毕赤酵母生产系统，为该品的进一步开发和应用奠定了基础。